Photonic implementation of jamming avoidance response

Patent metadata

Field	Value
Publication number	US-10432304-B2
Application number	US-201815947179-A
Country	US
Kind code	B2
Filing date	Apr 6, 2018
Priority date	Oct 27, 2015
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Various examples are provided for jamming avoidance response (JAR), and photonic implementations thereof. In one example, a method includes generating optical pulses that correspond to raising envelope of a beat signal associated with an interference signal and a reference signal; generating optical spikes that correspond to positive zero crossing points of the reference signal; and providing a phase output that indicates whether the beat signal is leading or lagging the reference signal, the phase output based at least in part upon the optical spikes. An adjustment to a reference frequency can be determined based at least in part upon the optical pulses and the phase output. In another example, a JAR system includes photonic circuitry to generate the optical pulses; photonic circuitry to generate the optical spikes; and photonic circuitry to provide the phase output. A logic unit can determine the adjustment to the reference frequency.

First claim

Therefore, at least the following is claimed:

1. A jamming avoidance response (JAR) system, comprising:
circuitry configured to transmit a reference signal and receive an interference signal;
photonic circuitry configured to generate optical spikes corresponding to positive zero crossing points of the reference signal; and
photonic circuitry configured to provide a phase output that indicates whether a beat signal associated with the interference signal and the reference signal is leading or lagging the reference signal, the phase output based at least in part upon the optical spikes and the beat signal.

2. The JAR system of claim 1 , further comprising signal beating circuitry configured to generate the beat signal from the interference signal and the reference signal.

3. The JAR system of claim 1 , further comprising photonic circuitry configured to generate optical pulses corresponding to rising edges of an envelope of the beat signal.

4. The JAR system of claim 3 , further comprising logic unit circuitry configured to determine an adjustment to a reference frequency of the reference signal based at least in part upon the optical pulses and the phase output.

5. The JAR system of claim 3 , wherein the photonic circuitry configured to generate the optical pulses corresponding to the rising edges of the envelope of the beat signal comprises:
a first electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon an envelope signal corresponding to the beat signal;
a second EOM configured to generate an inverted amplitude modulated optical signal based upon the envelope signal; and
a non-linear optical device that generates the optical pulses from a combined optical signal produced from the amplitude modulated optical signal and a delayed version of the inverted amplitude modulated optical signal.

6. The JAR system of claim 5 , wherein the non-linear optical device is a length of highly nonlinear fiber (HNLF), a semiconductor optical amplifier (SOA), a silicon wire waveguide or a photonic crystal fiber.

7. The JAR system of claim 5 , wherein the photonic circuitry configured to generate the optical pulses corresponding to the rising edges of the envelope of the beat signal further comprises a bandpass filter configured to filter the optical pulses from the non-linear optical device.

8. The JAR system of claim 1 , wherein the photonic circuitry configured to generate the optical spikes corresponding to the positive zero crossing points of the reference signal comprises:
an electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon the reference signal;
a thresholder configured to clamp an amplitude of the amplitude modulated optical signal to generate a clamped optical signal; and
a non-linear optical device that generates the optical spikes from the clamped optical signal.

9. The JAR system of claim 8 , wherein the photonic circuitry configured to generate the optical spikes corresponding to the positive zero crossing points of the reference signal further comprises a bandpass filter configured to filter the optical spikes from the non-linear optical device.

10. The JAR system of claim 1 , wherein the photonic circuitry configured to provide the phase output that indicates whether the beat signal is leading or lagging the reference signal comprises:
an electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon the beat signal; and
a semiconductor optical amplifier (SOA) configured to generate the phase output from a combined optical signal produced from the amplitude modulated optical signal and the optical spikes from the photonic circuitry configured to generate the optical spikes corresponding to the positive zero crossing points of the reference signal.

11. The JAR system of claim 10 , wherein the photonic circuitry configured to provide the phase output that indicates whether the beat signal is leading or lagging the reference signal further comprises a bandpass filter configured to filter the phase output from the SOA.

12. A jamming avoidance response (JAR) method, comprising:
generating optical pulses that correspond to a rising edge of an envelope of a beat signal associated with a transmitted reference signal and a detected interference signal;
generating optical spikes that correspond to positive zero crossing points of the transmitted reference signal; and
providing a phase output that indicates whether the beat signal is leading or lagging the transmitted reference signal, the phase output based at least in part upon the optical spikes.

13. The JAR method of claim 12 , wherein generating the optical pulses comprises:
generating an amplitude modulated optical signal based upon an envelope signal corresponding to the beat signal;
generating an inverted amplitude modulated optical signal based upon the envelope signal; and
generating the optical pulses from a combined optical signal produced from the amplitude modulated optical signal and a delayed version of the inverted amplitude modulated optical signal.

14. The JAR method of claim 13 , wherein a non-linear optical device generates the optical pulses from the combined optical signal.

15. The JAR method of claim 14 , wherein the non-linear optical device is a length of highly nonlinear fiber (HNLF), a semiconductor optical amplifier (SOA), a silicon wire waveguide or a photonic crystal fiber.

16. The JAR method of claim 12 , wherein generating the optical spikes comprises:
generating an amplitude modulated optical signal based upon the transmitted reference signal; and
clamping an amplitude of the amplitude modulated optical signal to generate a clamped optical signal for generation of the optical spikes.

17. The JAR method of claim 16 , wherein a non-linear optical device generates the optical spikes from the clamped optical signal.

18. The JAR method of claim 12 , wherein providing the phase output comprises:
generating an amplitude modulated optical signal based upon the beat signal; and
generating the phase output from a combined optical signal produced from the amplitude modulated optical signal and the optical spikes.

19. The JAR method of claim 18 , wherein the phase output comprises an optical spike having an amplitude that indicates whether the beat signal is leading or lagging the transmitted reference signal.

20. The JAR method of claim 12 , further comprising determining an adjustment to a reference frequency of the transmitted reference signal based at least in part upon the optical pulses and the phase output, wherein the reference frequency is increased when the phase output indicates a leading beat signal and the optical pulses indicate an increasing amplitude, or when the phase output indicates a lagging beat signal and the optical pulses indicate a decreasing amplitude.

Assignees

• Univ Georgia

Inventors

• Fok Mable P
• Toole Ryan

Classifications

• H04B10/80

  Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water · CPC title

• H04B10/0775 Primary

  Performance monitoring and measurement of transmission parameters · CPC title

• H04B10/508

  Pulse generation, e.g. generation of solitons · CPC title

• H04K3/827

  using characteristics of target signal or of transmission (as countermeasure against jamming H04K3/25), e.g. using direct sequence spread spectrum or fast frequency hopping (spread spectrum techniques H04B1/69) · CPC title

• H04K3/25

  based on characteristics of target signal or of transmission (as countermeasure against surveillance H04K3/827), e.g. using direct sequence spread spectrum or fast frequency hopping (spread spectrum techniques H04B1/69) · CPC title